The skill and knowledge of doctors affect the in-hospital mortality. Recent documented studies in this regard are scant. In this study in-hospital mortality of patients at Ghaem children’s hospital - Hamadan for 6 consequent years (1989-1995) was investigated.In the first 3 - year (1st p) patients were firstly managed by the interns who worked under supervision of an in-hospital GP. In the second 3-year (2nd p) a full time residency was established in the hospital and the patients were firstly handled by the residents. In both periods an on-call service of the attending pediatricians was available. Number of admissions in 1st p and 2nd p were 5804 and 5663 respectively. Number of deaths in 1st p were 735 and in 2nd p 309. Number of deaths in the first day after admission in 1st p were 448 (7.6% of admissions) and in 2nd p125 (2.4% of admissions). Number of deaths after the 1st day of admission in 1 st p was 287and in 2nd p 184. Distribution of the patients by sex, age, causes of death, dwelling area, maternal education, weight for age, duration of admission was not considerably different in both periods. Number of the attending medical staff, nurses, and also the therapeutic and paramedical facilities were similar in both periods. Reduction in mortality rate was conspicuously more in the 1st day after admission and less in the neonatal period. Higher quality of medical services lowers hospital mortality.